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研究杨木在不同条件下的高温预水解反应,探讨预水解温度、保温时间、液比及预水解因子(P因子)等对预水解的影响。研究结果表明:随着反应温度、保温时间及液比增大,预水解后杨木得率降低,预水解液(PHL)的pH值降低,固形物含量、酸溶木素含量和聚戊糖提取率升高,预水解温度过高(≥180℃),易发生木素或LCC吸附、沉积现象,不利于半纤维素的提取;P因子能较好地控制预水解反应,且相同的P因子条件下,所得预水解后的木片及PHL相关结果相近。通过P因子优化实验,得到杨木高温预水解的优选工艺条件为:预水解温度170℃,保温时间60min,相应的P因子约764h,液比5:1。
The pre-hydrolysis of poplar under different conditions was studied. The effects of pre-hydrolysis temperature, incubation time, liquid ratio and pre-hydrolysis factor (P) on the pre-hydrolysis were discussed. The results showed that with the increase of reaction temperature, holding time and liquid ratio, the yield of poplar decreased after pre-hydrolysis, the pH value of pre-hydrolyzate (PHL) decreased, the content of solid, the content of acid-soluble lignin Extraction rate increased, pre-hydrolysis temperature is too high (≥ 180 ℃), prone to lignin or LCC adsorption and deposition phenomena, is not conducive to the extraction of hemicellulose; P factor can better control the prehydrolysis reaction, and the same P Factor conditions, the resulting pre-hydrolyzed wood and PHL-related results are similar. Through P-factor optimization experiment, the optimal technological conditions for pre-hydrolysis of poplar wood were as follows: pre-hydrolysis temperature 170 ℃, holding time 60min, corresponding P factor 764h, liquid ratio 5: 1.